SU1155402A1 - Apparatus for monitoring the welding duties of automatic arc-welding machine - Google Patents

Abstract

DEVICE OF CONTROL OF ARM AUTOMATIC WELDING MODES, containing a relay group connected to a resistor unit, and a switching circuit connected to a power source, while one of the outputs of the device is connected to the welding system control system, characterized in that the quality of welded joints by automating the welding process; the switching circuit consists of a coincidence circuit, a current presence sensor in the welding circuit, a voltage sensor, short circuits, a control and protection unit, a start relay and The sensor outputs are connected to a relay group through a coincidence circuit, the first output of the short circuit counter is connected to a voltage sensor, and the second is connected to the first brightness control and protection input, the second input of which is connected to the output of a current presence sensor in the welding circuit, output through the start relay to the control input of the key, the information input of which is connected to the input of the switching circuit.

Description

The invention relates to devices for automatic welding and can be used in automatic arc welding systems with robotic arms. The conditions of operation of the robot manipulator in conjunction with the welding equipment always require special measures to ensure coordinated work. In the aggregate of the jointly operating equipment, the robot role is assigned to the robot as the mechanism that performs the most complex functions. Therefore, its control system provides for the possibility of issuing a series of commands to external equipment, with the help of which the operation of the whole complex is ensured. These teams are divided into two groups. Commands to enable previously disconnected control devices of external technological equipment with the supply of which interrupt the robot's reproduction of a predetermined program prior to the arrival in its control system of signals confirming that the command given was executed (loading unloading, orientation). Commands for switching external equipment devices, the flow of which does not interrupt the robot's reproduction of the program (selection, correction, and switching of welding modes). The purpose of the invention is to improve the quality of welded joints by automating the welding process, while improving reliability and reducing costs due to the expansion of technological capabilities without the involvement of additional technical means. I The goal is achieved by the fact that the device controls the welding modes of an arc machine (welding controller), contains a relay group connected to a resistor unit, and a switching circuit connected to a power source, while one of the outputs of the device is connected to a welding system control system , the switching circuit consists of a coincidence circuit, a current presence sensor in the welding circuit, a voltage sensor, a short circuit counter, a control and protection unit, a start relay and a key, 22 while the sensor outputs through it matcher connected to the relay group, the first output counter short circuits connected If. the voltage sensor, and the second to the first input of the control and protection unit, the second input of which is connected to the output of the current presence sensor in the welding circuit, and the output via the start relay to the control input of the key, whose information input is connected to the input of the switching circuit. FIG. 1 is a block diagram of the device; in fig. 2 is a diagram of the sequence of operation of the circuit during the normal course of the welding cycle in FIG. 3 - the same, in the absence of excitation of the arc as a result of various faults or when it is broken during the welding cycle; in fig. 4 - turning on the device in the welding complex. The principal scheme of the nodes according to the proposed block diagram of the device can be performed using known devices and is determined by the composition of the welding complex. The device for monitoring the welding modes of the arc machine to the robotic welding complex includes (Fig. 1): power supply 1, switch 2, counter 3 short circuits, voltage sensor 4, current presence sensor 5 (in the welding circuit), control and protection unit 6, cycle start relay 7, coincidence circuit 8, relay group 9, and register block 10. The device works as follows. The voltage from the power source through the key (relay contact or transistor controlled by R5 / trigger) is sent to the functional units of the device by the signals of the start-up, cycle relay. At the same time, certain voltage levels are set at the input of the short circuit counter. Simultaneously with the beginning of the supply of the electrode wire, the counting of time to the control and protection units begins. The control and protection unit records the fact of normal ignition of the arc and gives permission to continue the welding cycle. In the absence of ignition of the arc or disruption of its burning process, the unit turns off the power source of the device and issues

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a signal to the control system of the complex to turn off the burner cycle and move the manipulator to its initial position. The fixing of the fact of ignition of the arc by the control and protection unit is carried out by changing the voltage value at the source of the welding current and the presence of current in the welding circuit. This is as follows. When the electrode touches the surface of the product being welded, the voltage at the output of the welding current source (the no-load voltage) drops sharply in a period of time of several tens of milliseconds, after which an arc occurs.

The signals from the current sensor and the arc sensor are fed to a coincidence circuit, which includes, if both signals are present, or does not include, in the absence of at least one signal, an executive relay group. Simultaneously with the switching on of the relay group, the control and protection unit is transferred to the standby state and monitors the arc. When the actuating unit of the relay group is triggered, a signal is fed to the resistor unit (control circuit of the electrode wire feed speed).

Thus, the relay group commutates the resistors in the motor control circuit of the electrode wire feeder.

The turn-on signal of the welding cycle is supplied in the form of a constant voltage level. From the control system of the welding complex (Fig. 2B), which holds time tu. When the electrode touches the welded product, the voltage of the welding current source first drops from idle to zero, and then recovers to the operating voltage Ug (Fig. 2p). At the input of the counter and protection unit, the potential of the current sensor is maintained until; in the welding circuit current flows (Fig. 2 g). After the voltage level has been restored to the value of Vf, after a time tj (Fig. 2e), the arc voltage sensor outputs a signal to the comparison circuit, to which the signal from the current sensor has already been applied. After a period of time, the signals from the sensors are removed. At the initial moment of time.

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corresponding to i. , the wire feed rate f is underestimated. The time interval ip is the time for the} end of the electrode to the product and the ignition of the arc.

After the ignition of the arc, the speed changes to the working value and is maintained at this level until

10 start welding crater. In addition, an arc ignition signal is sent to the complex control system. Crater welding is performed by varying the speed of movement.

d the torch (welding speed) and the feed rate of the electrode wire (welding current). Modes are pre-selected and set on the potentiometers of the resistor unit. Switching the welding modes to the crater welding mode is carried out in the device by switching the relay group. When the welding signal is removed, the supply of electrode wire stops. In time ip

the wire burns and the arc cuts off: s.

If the arc is not ignited, for example, due to a violation of the electrical contact when the wire touches the product, or as a result of welding the electrode wire with the product (Fig. 3), then the device disconnects the power supply of the remote signal after a time tj

 Stop cycle from the control unit and

protection on the cycle start relay and the key is open.

In addition, a signal is inserted into the control system of the welding robot to stop the manipulator and retract it to its original position. During the welding process, hey is also continuously monitored by the presence of current in the welding circuit (4ig. 5). When an arc is broken (current disappears in the welding circuit), the control and protection unit's eremen counting circuit is switched on, which, in the absence of current at the specified 0 time ij, turns off the power supply circuit of the device. At the same time, the time reading circuit is also turned off, which provides cooling of signals from the arc sensor and the TOS sensor k. The timing circuit is included in the control and protection unit. ; in the normal mode, after switching off the welding cycle, the circuit is restored to the initial state automatically: the power supply is released and the commands are not issued. In a typical robotic welded complex, a robot controller is installed (Fig. 4), on which welding torch 11 is mounted. The welding machine is powered from a current source 12 connected to an electrode wire feeding device t3. The connection of the arc machine and the robot-manipulator is carried out through the device 14 to control welding modes. A magnetically controlled sensor 5 is mounted on the current supply cable 15. The control device 14 has separate outputs: 16 - to the control panel of the unit up / short tic (3)

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Claims (1)

ARC AUTOMATIC WELDING MODE CONTROL DEVICE, comprising a relay group connected to a resistor block and a switching circuit connected to a power source, one of the device outputs being connected to a control system of the welding complex, characterized in that, in order to improve the quality of welded joints by automating the welding process, the switching circuit consists of a matching circuit, a current sensor in the welding circuit, a voltage sensor, a short circuit counter, a control and protection unit, a start relay and a key ca, while the outputs of the sensors through the matching circuit are connected to the relay group, the first output of the short-circuit counter is connected to the voltage sensor, and the second to the first input of the monitoring and protection bus, the second input of which is connected to the output of the current sensor in the welding circuit, and ' output through the start relay to the control input of the key, the information input of which is connected to the input of the switching circuit. SU „1155402 ¹ 1155402